The present invention relates to safety supports for vehicle tires, which are mounted inside the tires on their wheel rims in order to take up the load in the event of tire failure. In particular, it proposes an improved support essentially made of a flexible elastomeric material.
The use of a safety support of annular shape made of a flexible elastomeric material has been known for a very long time. Such a support has the advantages of not being sensitive to impacts, of offering good stability of performance over time and of not causing too pronounced a deterioration of the behavior of the tire if it has to run flat.
By contrast, such a support has two major defects: unacceptable weight, bearing in mind the current requirements of motor manufacturers to reduce the weights of the axles of their vehicles, and highly insufficient endurance under run-flat conditions as a result of the heating-up of the material which is likely to lead to very swift thermal degradation.
In order to solve these defects, Patent Application FR 2 532 591 proposes a safety support essentially made of elastomeric material in the shape of an H which is symmetric relative to a longitudinal mid-plane with a wide circumferential channel in its radially lower part for lightening it and reducing its rigidity, the circumferential channel in its radially outer part being a housing for a strap for holding the support on the wheel rim. This support effectively gives a lower weight and acceptable endurance, but at the expense of the support having a radial rigidity which is relatively high because it is higher than 750 kg/cm, which detracts from the quality of the behavior of the tire under run-flat conditions.